1. Field of the Invention
The invention relates to a dust arrester, more particularly to a dust arrester for a sanding machine.
2. Description of the Related Art
Tiny dirt particles are produced whenever a sanding machine is used to smooth or polish the surface of a metal or wooden workpiece. These dirt particles pollute the surrounding environment and can be harmful to one's health. At a time when environmental pollution is taken seriously into account, it is highly desirous to improve the present working environment by making it cleaner and healthier.
A dust arrester is used to collect the tiny particles produced when performing a sanding operation. In a first kind of conventional dust arrester, one side of the housing of this dust arrester is provided with a suction conduit. The suction conduit is communicated with the air outside the workshop. A suction unit is then used to draw the dirt particles into the suction conduit. Dirt particles inside the suction conduit are collected by a dust handling means which is provided near one end of the suction conduit. This kind of a dust arrester has a relatively high cost and is ineffective in controlling air pollution.
In a second kind of conventional dust arrester, a plurality of dust collecting pipes are provided inside the housing of the dust arrester. A passage connects the bottom ends of the dust collecting pipes. A suction unit and a motor are provided on one side of the housing. The motor actuates the suction unit to draw air through the dust collecting pipes and into the passage. Dirt particles are collected on the walls of the dust collecting pipes. After a period of use, a vacuum unit (the suction force of which is greater than that of the suction unit) is used to draw the dirt particles from the dust collecting pipes for the collection thereof in a dust receiving bin. Although this kind of dust arrester is more effective in controlling air pollution, it requires the use of a vacuum unit and thus has a relatively higher cost.